PGM-FI System Description - Injection Control (A/T, M/T)
Fuel injection controls include fuel injection amount control, fuel cut control, and fuel pump control. Adopting PGM-FI (programmed-fuel injection) technology enables accurate fuel controls, which contributes to increased engine power and decreased fuel consumption.
Fuel Injection Duration
The fuel injection duration is determined by adding correction values to a basic injection duration. The engine control module (ECM)/powertrain control module (PCM) controls the amount of fuel injection by the length of time the injector is energized.
Fuel Injection Timing
The fuel injection timing is determined by the ECM/PCM, which calculates the injection time for each cylinder based on the signals from the crankshaft position (CKP) sensor and the camshaft position (CMP) sensor. The ECM/PCM then controls the time to energize the injector. In addition, the fully sequential injection system is adopted as a fuel injection system.
CKP Sensor, CMP Sensor (Except K24Z7 Engine)/CMP Sensor B (K24Z7 Engine)
The CKP sensor is attached to the cylinder block. Each of the 58 teeth on the CKP pulse plate passes over it, a pulse signal is delivered to the ECM/PCM. The CMP sensor or CMP sensor B is attached to the cylinder head. Every time one of the three protrusions of the CMP pulse plate attached to the camshaft passes over it, a pulse signal is delivered.
Fuel Injector
The fuel injector for fuel supply has multiple holes. A nozzle with multiple holes increases fuel atomization and improves the mixing with the surrounding air. When the coil in the injector is energized, the plunger is pulled in. The needle valve, which is integral with the plunger, is pulled fully. Then, the injector sprays the pressurized fuel which is controlled by the fuel pressure regulator.
MAF Sensor/IAT Sensor
The mass air flow (MAF) sensor and an intake air temperature (IAT) sensor are installed at the outlet of air cleaner to detect the amount of intake air and the intake air temperature. Within the mass air flow is a hot wire, cold wire and IC. As air passes the heated hot wire, the resistance changes as it is cooled by the airflow. This is used to detect the amount of intake air. The control circuit installed in the IC detects the resistance of the hot wire and the cold wire so that temperature difference between the hot wire and the cold wire is held constant. The intake air quantity is calculated based on the current value and voltage that is input to the ECM/PCM. The IAT sensor uses a thermistor that changes resistance changes depending on the intake air temperature. This causes a changing voltage that is input to the ECM/PCM.